#include<stdio.h>
int main()
{
    //printf("hello world\n");
    //printf("hello world\n");
    //printf("hello world\n");
    //printf("hello world\n");
    //printf("hello world\n");
    printf("hello world\n");

    //#define VERSION1 1
    //#define VERSION2 2

    #ifdef VERSION1 
    printf("hello version1\n");
    #elif VERSION2 
    printf("hello version2\n");
    #else
    printf("hello unkown version\n");
    #endif


    return 0;
}
